time.c: fix non-terminated string

* time.c (month_arg, time_strftime): RSTRING_PTR() may not be
  NUL-terminated.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@45630 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
* 2014-04-19

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@45631 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
fix typo

* NEWS, README.EXT: fix typo.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@45632 b2dd03c8-39d4-4d8f-98ff-823fe69b080e